The co-occurrence of child maltreatment and parental substance abuse is a major public health problem with serious consequences for children, parents, families, and the community at large. The need for effective dual treatment of caregiver substance abuse and child maltreatment is unquestionable, but there is a dearth of controlled treatment outcome studies with substance-abusing parents who have engaged in child maltreatment. This project examines two evidence-based treatments-Contingency Management for substance abuse and Pathways Triple P parenting intervention to improve parenting and address child maltreatment. The main study is a longitudinal, factorial, randomized controlled trial to gauge impact on outcome variables that include parental substance abuse, parenting-related functioning (parenting practices, child-maltreatment recidivism, observed parent-child interaction), child adjustment, parent's HIV behavioral risk, and parental quality of life. The sample includes parents in the child welfare system that is struggling with substance-abuse difficulties and has at least one child 2-8 years of age. The study design and implementation features are rigorous and build on adequate statistical power, careful randomization procedures preserving an intent-to-treat model, multiple sources of data (i.e., toxicology samples, self-report, observation, CPS data, treatment records, and teacher report), procedures for promoting and verifying treatment fidelity, an analytic framework centering on random-intercept linear growth models and inclusion of 12 and 18 month follow-up assessments. A second study draws on part of the first study and focuses on potential correlates or predictors of individual variabilty in outcome with the dual treatment, such as parent age and education, level of socioeconomic disadvantage, psychological distress, family difficulties, and legal difficulties. The results of tis project will inform the field about how well the combination of state-of-the-art treatments for substance abuse and child maltreatment impacts families in the child welfare system and move closer to reducing the misery and societal costs associated with these serious public health problems.